DOSING UNIT FOR POWDER OR PARTICULATE MATERIAL AND DISTRIBUTION MACHINE WITH SUCH A DOSING UNIT

Description

[0001] The invention relates to a dosing unit for powdered and / or particulate distribution material, in particular seed and / or fertilizer, comprising a dosing roller with at least two dosing wheel segments, which is mounted in a dosing housing with an inlet and an outlet. Each dosing wheel segment is assigned an independently operable shut-off valve to deactivate one or more dosing wheel segments as needed. The invention further relates to a distribution machine, in particular a seed drill or fertilizer spreader, comprising at least one such dosing unit.

[0002] Such dosing units are used particularly in pneumatic distribution machines, such as pneumatic seed drills, seed drills, and pneumatic fertilizer spreaders, so-called blower spreaders. Such pneumatic distribution machines exist in lightweight designs as attachments that can be coupled to the three-point linkage of a tractor, while in heavy-duty designs they can be mounted on an axle-supported trailer or a self-propelled vehicle. They typically comprise a plurality of laterally projecting outward-facing booms that accommodate distribution lines ending at different distances from one another. A blower is used to convey the material to be distributed. The pressure line of the blower is connected to the outlet of each dosing unit and opens into a pressure distributor, to which several distribution lines are connected.Injectors arranged between the pressure distributor and the distribution lines can be used to transfer the material to be spread from the dosing units to the distribution lines, ensuring that each distribution line receives the same amount of spreading material. Alternatively, only one conveying line can be connected to the outlet of each dosing unit, which leads into or into a respective distribution head, from which a plurality of distribution lines branch off. The material to be spread is finally conveyed pneumatically via the outwardly deflected distribution lines to their ends, where it hits distribution elements, which are usually formed by impact plates or coulters, and from there is deposited on the ground in a substantially fan-shaped manner (in the case of impact plates) or roughly linearly (in the case of coulters), or is introduced into a furrow created in the soil.The main advantage of pneumatic spreaders over disc spreaders equipped with distributor discs is that they can achieve a more even distribution of the spreading material over a larger spreading width. Such a pneumatic spreader is known, for example, from DE 10 2004 030 240 A1.

[0003] For dosing the distribution material, such as essentially powdered and / or particulate seed and / or fertilizer or possibly also other granules, e.g. used for plant protection, dosing units have proven particularly useful in pneumatic distribution machines. These dosing units comprise a rotationally driven dosing roller mounted in a dosing housing with an inlet and an outlet, whereby the inlet is usually located on the top side of the dosing housing and the outlet on its underside. By changing the rotational speed of the dosing roller, which usually has two or more dosing wheel segments, e.g. in the form of cam and / or cell wheel segments, the dosed quantity of the distribution material enriched in the cam valleys arranged between the cam peaks or in the cells can be easily controlled.

[0004] The shape of the metering wheel segments must always be adapted to the respective seed and / or fertilizer type to ensure proper metering with the desired mass flow and avoid even local under- or over-metering. This is primarily due to the fact that different metering rollers are required for particulate fertilizers and for seed that is also particulate but has finer particles and is significantly more sensitive to mechanical influences. For fertilizers, the aforementioned cam rollers are primarily the method of choice because the usually hygroscopic fertilizer particles tend to stick to the metering roller and are practically impossible to remove from metering rollers in the form of cellular wheel rollers, at least during operation.On the other hand, such build-up can be removed from cam rollers using suitable cleaning devices, even during operation. Such cleaning devices can comprise pins that engage between the cam crests of the cam roller and / or between individual cam wheels or discs that form the cam roller, in order to be able to "scrape off" adhering fertilizer particles from the cam roller. For the precise metering of seed, on the other hand, other types of metering rollers are the method of choice, such as cell wheel and cell wheel segment rollers, as well as perforated or grooved rollers, the outer surface of which is equipped with hole-like or, in particular, groove-shaped depressions extending in the circumferential direction, which can gently hold the seed to be metered. The individual cells of the cell wheel or cell wheel segment rollers orthe recesses of the perforated or grooved rollers are sealed against the metering housing by resting against a complementary sealing surface of the metering housing or by being spaced from it by a narrow gap in the manner of a gap seal.

[0005] A distribution machine equipped with a plurality of metering units with rotary-driven metering rollers can be found, for example, in EP 2 786 649 B1. In order to adapt the metering units to different types of material to be distributed, such as in particular different types of seeds and / or fertilizers, the individual metering wheel segments of the metering roller, which are designed as cam and / or cellular wheel segments and, if necessary, as perforated or grooved rollers, can be exchanged. For this purpose, however, the metering roller must be disassembled and reassembled with the desired combination of metering wheel segments, which requires a certain amount of effort on the part of the operator.

[0006] WO 2017 / 138867 A1 describes a dosing unit with a dosing roller consisting of one or two cell wheels for powdered or particulate material to be distributed in agricultural distribution machines, in particular in the form of pneumatic distribution machines. An insert is arranged in the dosing unit to ensure sealing against the penetration of air into the dosing housing. In the case of a dosing roller comprising two cell wheels, a gate valve is also provided, the relative position of which with respect to the cell wheels is adjustable in the axial direction in order to change the amount of material fed to the cell wheels and thus adapt it to different target mass flows of material to be distributed. The gate valve is designed like a partial ring, which completely covers one of the cell wheels when it is displaced in the axial direction. The gate valve is actuated, in particular, manually using an adjusting screw.In addition to the relatively complex design of the dosing unit, a particular disadvantage is the fact that essentially only one of two cellular wheels can be activated or deactivated in this way, while multiple dosing wheel segments cannot be switched on or off independently of one another. Furthermore, remote control of the gate valve would be desirable, so that the operator does not have to interrupt the distribution process when activating or deactivating individual dosing wheel segments.

[0007] US 2016 / 0120113 A1 discloses another dosing unit for distribution material using agricultural machinery. This unit comprises a dosing roller with several dosing wheel segments separated from each other by separating rings. To activate or deactivate individual dosing wheel segments of the dosing roller, an axially movable shut-off valve is provided. This valve extends between the inlet of the dosing housing and the dosing roller and is adjustable by means of a toothed rack and a gear meshing therewith. In this case, too, only the outer dosing wheel segments can be activated or deactivated by means of the shut-off valve, and individual activation or deactivation of individual - arbitrary - dosing wheel segments is not possible.In addition, due to its length, which roughly corresponds to the width of the metering roller, the gate valve requires considerable installation space, which is only available to a limited extent in distribution machines of this type. The same applies to another embodiment described in US 2016 / 0120113 A1, according to which the metering roller itself is axially displaceable and interacts with a stationary shut-off device in the form of a sleeve.

[0008] EP 2 832 202 A1 describes a seed drill with a dosing unit having a dosing housing in which two dosing wheels arranged next to one another are mounted, such as a normal dosing wheel on the one hand and a fine dosing wheel on the other, which are separated from one another by means of a partition wall arranged detachably or removably on the housing. A shut-off slide is assigned to each dosing wheel in order to optionally interrupt the dosing of one or the other dosing wheel or both dosing wheels. The shut-off slides, which can be manually operated independently of one another, can be moved along the inlet of the dosing housing approximately tangentially in relation to a respective dosing wheel. In this way, individual activation or deactivation of each dosing wheel for opening or closing is possible.Closing a respective gate valve is possible, but these gate valves, in turn, require a very large installation space, which is very limited in distribution machines of this type. The same applies to a motorized drive of the gate valves, which, however, is not provided for in the document. A similar dosing unit is described in EP 2 832 203 A1.

[0009] US 2012 / 0174844 A1 discloses a seed metering unit comprising a metering housing arranged below an inlet hopper, having an inlet and an outlet according to the preamble of claim 1. A metering roller is rotatably mounted in the metering housing, which comprises a plurality of metering wheel segments mounted on a shaft, each of the individual metering wheel segments being assigned to a pair of distribution lines. Each metering wheel segment is assigned an independently operable shut-off valve, each of which comprises an actuating lever hinged to a bracket below the metering housing and a curved inner circumferential section arranged at its free end, which can be pivoted back and forth between an open position and a closed position. Apart from the relatively complex design, this also requires a very large installation space.

[0010] US 2017 / 0118905 A1 describes a metering device for dispensing fertilizer or seed for an agricultural distribution machine. The device has a metering housing with a plurality of chambers, each of which houses a metering wheel segment of the metering roller. To separate individual metering wheel segments from the supplied flow of material, shut-off elements are provided. These are arranged between the inlet of the metering housing and a respective metering wheel segment rotating in a respective chamber. The shut-off elements can be designed as clips or in the form of replaceable frame parts and must be manually assembled and disassembled, which proves to be relatively complex and laborious.

[0011] Another dosing unit is known from US 5 024 356 A, which is intended in particular for particulate distribution materials, such as fertilizer. The dosing unit comprises a dosing wheel which is mounted in a dosing housing and is driven in rotation by a controlled motor, the dosing housing being equipped with an upper inlet and a lower outlet, as well as a gate valve assigned to the inlet. The gate valve has a substantially circular arc-shaped inner circumference and serves to change the opening cross-section of the inlet as well as to completely block off the entire inlet cross-section and is mounted in the dosing housing directly adjacent to the outer circumference of the dosing wheel. This is achieved by means of bearings which are mounted coaxially to the dosing wheel. A hollow shaft of the gate valve which is arranged coaxially to the dosing wheel is connected to a motor drive on the front side in order to bring the gate valve into the desired position.

[0012] Furthermore, instead of gate valves, hinged butterfly valves are known inside the metering housing (DE 10 2016 208 320 A1), but their external drive also proves to be complex, whereby such butterfly valves have the particular disadvantage that when closing at high closing forces they have to displace the distribution material located between the butterfly valve and the metering roller, which in practice is accompanied by relatively long closing times and partial destruction of sensitive distribution materials, such as seeds.

[0013] The invention is based on the object of developing a dosing unit of the type mentioned at the outset and a distribution machine equipped with at least one such dosing unit, while at least largely avoiding the aforementioned disadvantages, in a simple and cost-effective manner in such a way that, with a very compact design of the dosing unit, individual activation of the individual dosing wheel segments of the dosing roller by means of a respective gate valve is possible independently of one another, wherein in particular not only manual but also remote-controlled actuation of the gate valves should be ensured.

[0014] According to the invention, this object is achieved by a dosing unit having the features of claim 1. In particular, the object is achieved in that the gate valves are mounted in the interior of the dosing housing and have a blocking surface inclined in the axial direction, wherein the gate valves have a substantially circular arc-shaped inner circumference and can be actuated in the circumferential direction of a respective dosing wheel segment of the dosing roller between a blocking position, in which they are arranged between the inlet and / or the outlet and the respective dosing wheel segment and deactivate the respective dosing wheel segment, and at least one open position, in which the inlet and the outlet are connected to the respective dosing wheel segment.

[0015] To achieve this object, the invention provides for a distribution machine of the type mentioned at the outset, such as in particular a seed drill or a fertilizer spreader, to be equipped with at least one such metering unit.

[0016] Due to the fact that each dosing wheel segment is assigned an independently operable shut-off valve, the width of which is adapted to the axial width of each dosing wheel segment, the design according to the invention enables individual activation or deactivation of the individual dosing wheel segments independently of one another, individually or in groups, so that the desired mass flow of distributed material can always be taken into account without excessively reducing or increasing the speed of the dosing roller. While the shut-off valves in the prior art require a large installation space in order to be able to translate or pivot them between their opening and shut-off or closing positions, primarily outside the dosing housing.In order to be able to displace the metering unit into the closed position, the design according to the invention ensures the greatest possible compactness of the metering unit due to the shut-off valves which can be rotated around the circumference of a respective metering wheel segment of the metering roller and are provided with an approximately circular arc-shaped inner cross-section, which extend between the inlet and / or the outlet of the metering housing and the metering roller, which enables it to be installed in practically any known distribution machine, including pneumatic distribution machines with very limited installation space, wherein it is also possible to exchange a conventional metering unit for a metering unit according to the invention.With a view to achieving the greatest possible compactness, the invention provides that the gate valves are mounted inside the dosing housing, so that only any handles for actuating the gate valves and / or any drives of the gate valves can be arranged outside the dosing housing, for example fastened to it.

[0017] According to the invention, the gate valves have a shut-off surface inclined in the axial direction, wherein the outer circumference of the shut-off surface of each gate valve decreases inward, in particular from a respective outer side of the metering housing. In this way, the accumulation of residues of the distribution material on the upper side of each gate valve facing the inlet of the metering housing is prevented by allowing the distribution material to slide along the inclined shut-off surfaces of gate valves placed in the shut-off position in the axial direction of the metering roller until it falls through an open gate valve into the associated metering wheel segment of the metering roller.

[0018] To prevent material to be distributed from remaining in the dosing roller during a prolonged shutdown of individual dosing wheel segments of the dosing roller by means of one or more shut-off valves, it can prove advantageous if the shut-off valves can be actuated between the shut-off position, in which they are arranged between the inlet and the respective dosing wheel segment and deactivate the respective dosing wheel segment, and the at least one open position, in which the inlet is connected to the respective dosing wheel segment. In this way, the shut-off valves acting between the inlet of the dosing housing and the dosing roller can always leave the outlet open, so that the respective dosing wheel segment can always be emptied via the outlet.

[0019] In an advantageous embodiment, it can be provided that each gate valve can be operated independently of one another by means of a handle, for example in the form of a lever or the like arranged on the gate valve, in order to be able to move the gate valves back and forth independently of one another between their open position and their shut-off or closed position. The handle can in particular pass through the dosing housing, which for this purpose has, for example, an elongated hole assigned to each respective handle, within which the handle can be moved. While such manual operation of the gate valves can be provided exclusively, in an advantageous embodiment it can also serve solely for the purpose of emergency operation of the gate valves, which are otherwise equipped with a remote-controlled drive.

[0020] Accordingly, in an advantageous embodiment, it can be provided that a respective gate valve is assigned an independently controllable and / or adjustable, in particular electric motor or actuator, drive, wherein for such a remote-controlled drive of the gate valves, any known drive elements can be considered, such as hydraulic, pneumatic or electric piston / cylinder units or, in particular, electric motors, such as servo motors, etc.

[0021] A particularly robust drive arrangement capable of operating a respective gate valve at high adjustment speeds can be configured, for example, such that the drive of each gate valve comprises a threaded spindle, which can be rotated by a drive motor and along which a spindle nut is guided, engaging the threaded spindle and connected to a respective gate valve to actuate the gate valve by rotating the threaded spindle. The connection of each gate valve to the spindle nut can be achieved, for example, by means of an actuating means, such as a lever or the like, connecting a respective gate valve to a respective spindle nut.

[0022] In such an embodiment, the spindle nut can expediently have a slot extending substantially in the radial direction of the threaded spindle, in which the gate valve is hinged to the spindle nut, e.g. via its actuating means, in order to compensate for changes in distance due to the translational displacement of the spindle nut along the threaded spindle compared to the rotational displacement of the gate valve in the circumferential direction of the metering roller.

[0023] According to one embodiment of the dosing unit according to the invention, the drive of a respective gate valve can be arranged, for example, outside the dosing housing for the purpose of the simplest possible construction of the dosing unit while still maintaining a very high level of compactness. In particular, an elongated hole in the dosing housing assigned to a respective gate valve can serve to operatively connect a respective drive to a respective gate valve, through which an actuating means, such as a lever or the like, connects a respective gate valve to a respective drive. If the drive of a respective gate valve comprises a threaded spindle of the type mentioned above, this can be mounted in particular on an outer side of the dosing housing.Instead, according to a variant of the dosing unit according to the invention, the drive of each gate valve can also be arranged within the dosing housing, so that it is protected from external influences and practically integrated into the dosing unit. If the drive of each gate valve comprises a threaded spindle of the type mentioned above, this can be mounted, in particular, on the inside of the dosing housing.

[0024] With regard to the mounting of the gate valves in the circumferential direction of the metering roller inside the metering housing according to the invention, a structurally simple and cost-effective embodiment can provide for at least one end-face gate valve, in particular both end-face gate valves, to be mounted in a guide groove inside an end wall of the metering housing, so that the guide of at least the end-face gate valve(s) is / are integrated into the metering housing. In this context, "end-face" refers to the outside gate valves or—with respect to the metering wheel segments of the metering roller—the axially end-face gate valves.

[0025] As already indicated, due to the individual actuation of the gate valves independently of one another, the invention is particularly suitable for dosing units whose dosing roller has at least three or more dosing wheel segments, wherein a gate valve is assigned to each dosing wheel segment, so that any dosing wheel segments or any groups of dosing wheel segments can be activated and deactivated independently of one another by means of the respective gate valves.

[0026] If the metering roller of the metering unit has at least three metering wheel segments, it can be provided, with a view to a structurally simple and cost-effective mounting of a central gate valve or several central gate valves, that at least one gate valve assigned to at least one central metering wheel segment is mounted on a guide arranged in the interior of the metering housing, which guide surface is complementary to the substantially circular-arc-shaped inner circumference of the gate valve.

[0027] In order to ensure easy assembly and disassembly of the dosing unit, e.g. for the purpose of cleaning or maintenance, the guide arranged inside the dosing housing of the gate valve assigned to the at least one central dosing wheel segment can preferably be arranged on a dosing housing section which is detachably connected, e.g. screwed, to at least one end wall, in particular to both end walls, of the dosing housing.

[0028] Alternatively or in addition to mounting one or more central gate valves in a separate metering housing section, it may prove advantageous if at least one gate valve associated with at least one central metering wheel segment is mounted on an axially adjacent gate valve, wherein the axially adjacent gate valves, in particular, have complementary guide surfaces. Adjacent gate valves can thus engage with each other in such a way that, on the one hand, they are capable of guiding each other by means of the complementary guide surfaces, but, on the other hand, they can nevertheless be displaced independently of each other between their open and shut-off positions in the circumferential direction of the metering roller.

[0029] In order to prevent distribution material fed into a respective metering wheel segment via an open gate valve from falling into an adjacent metering wheel segment whose gate valve is in the shut-off position and thus causing incorrect metering, the metering wheel segments of the metering roller can preferably be separated from one another at their mutually facing axial ends by means of an annular wall. The annular walls can, for example, be parts of the metering roller and arranged between the individual metering wheel segments (the metering roller with the various metering wheel segments is, in this case, manufactured in one piece), or separate annular walls can be provided which can be slipped onto a shaft of the metering roller and are arranged between separate metering wheel segments (the metering roller in this case, for example,consists of individual dosing wheel segments that can be mounted on the shaft in a rotationally fixed manner, between which the separate annular walls are arranged).

[0030] As already indicated, the metering wheel segments of the metering roller can be formed by cam and / or cellular wheels, including perforated and / or grooved roller segments, which in particular have a different metering volume, in order to be able to activate or deactivate individual or groups of metering wheel segments individually by means of the gate valves according to the desired mass flow of the respective type of material to be distributed. It may prove expedient if at least one metering wheel segment is a standard metering wheel segment, while at least one other metering wheel segment is a fine metering wheel segment.

[0031] Further features and advantages of the invention will become apparent from the following description of an embodiment with reference to the drawings. Fig. 1 is a schematic side view of an embodiment of a pneumatic distribution machine viewed in the direction of travel; Fig. 2 is a schematic perspective view through an embodiment of a dosing unit of the distribution machine according to Fig. 1 ; Fig. 3 a schematic plan view of the dosing unit according to Fig. 2 from above; Fig. 4 a schematic side view of the dosing unit according to Fig. 2 and 3 ; Fig. 5 a schematic vertical section through the dosing unit according to Fig. 2 to 4 along the section plane VV of the Fig. 4 ; Fig. 6 a schematic perspective exploded view of the dosing unit according to Fig. 2 to 5 ; Fig. 7one of the Fig. 6 corresponding exploded view of the dosing unit, but from the opposite Fig. 6opposite side; Fig. 8A a schematic perspective view of the Fig. 6 right or in Fig. 7 left front wall of the dosing housing of the dosing unit; Fig. 8B a schematic side view of the front wall of the dosing housing according to Fig. 8A viewed from the inside of the dosing housing; Fig. 8C a schematic side view of the end wall of the dosing housing according to Fig. 8A and 8B from the Fig. 8B right side; Fig. 9A a schematic perspective view of the Figs. 6 and 7 middle dosing housing section of the dosing housing of the dosing unit, which is detachably connected to the end walls of the dosing housing; Fig. 9B a schematic side view of the middle dosing housing section according to Fig. 9A viewed from the inside of the dosing housing; Fig. 9C a schematic side view of the middle dosing housing section according to Fig. 9A and 9B from the Fig. 9Bleft side; Fig. 10A a schematic perspective view of the Fig. 6 left or in Fig. 7 right front wall of the dosing housing of the dosing unit; Fig. 10B a schematic side view of the front wall of the dosing housing according to Fig. 10A viewed from the inside of the dosing housing; Fig. 10C a schematic side view of the end wall of the dosing housing according to Fig. 10A and 10B from the Fig. 10B right side; Fig. 11A a schematic perspective detailed view of the Fig. 6 right or in Fig. 7 left gate valve; Fig. 11B a schematic side view of the gate valve according to Fig. 11A viewed in the axial direction of the metering roller; Fig. 11C a schematic side view of the gate valve according to Fig. 11A and 11B viewed in the radial direction of the metering roller; Fig. 12A a schematic perspective detailed view of the Fig. 6 and Fig. 7middle gate valve; Fig. 12B a schematic side view of the gate valve according to Fig. 12A viewed in the axial direction of the metering roller; Fig. 12C a schematic side view of the gate valve according to Fig. 12A and 12B viewed in the radial direction of the metering roller; Fig. 13A a schematic perspective detailed view of the Fig. 6 left or in Fig. 7 right gate valve; Fig. 13B a ​​schematic side view of the gate valve according to Fig. 13A viewed in the axial direction of the metering roller; Fig. 13C a schematic side view of the gate valve according to Fig. 13A and 13B viewed in the radial direction of the metering roller; Fig. 14A a schematic perspective view of a wall part of the metering housing section of the metering housing of the metering unit according to Fig. 9A to 9C ; Fig. 14B schematic side view of the wall part according to Fig. 14Aviewed from the inside of the metering housing in the radial direction of the metering roller; Fig. 14C a schematic side view of the wall part according to Fig. 14A and 14B viewed in the axial direction of the metering roller; Fig. 15A a schematic perspective detailed view of the metering roller of the metering unit; and Fig. 15B a schematic side view of the metering roller according to Fig. 15A .

[0032] The Fig. 1 The schematically illustrated distribution machine in the form of a pneumatic spreader and / or seed drill comprises a storage container 1 with two container parts, each having a conically tapered bottom 2, which slopes down to a respective outlet opening 3. The lateral boundaries of the storage container 1 are formed by lateral walls 4, which also taper downwards in the direction of the respective outlet opening 3. A dosing unit 5 is connected to the outlet openings 3 at the bottom, as will be described further below with reference to the Fig. 2 ff is explained in detail. Collecting trays 7 arranged below the dosing units 5 open into a section 8 of a conveying line 9, which leads outwards in opposite directions. The pneumatic distribution machine further comprises a blower 10, which is positioned, for example, in the central region of its longitudinal axis. From a pressure nozzle 11, 12 of the blower 10, an air distributor 13, 14 leads to the sections 8 of the conveying lines 9 in order to receive the metered distribution material, such as in particular spreading or seed. While in the schematic representation of the Fig. 1only one conveying line 9 is shown, it should be noted that in the area of ​​the transition between the air distributors 13, 14 to the conveying lines 9, in particular injectors (not shown) can be arranged, by means of which the gas flow supplied from the pressure nozzles 11, 12 is transferred into a plurality of conveying lines (not shown), such as a bundle of conveying or distribution lines, which finally transfer the spreading or seed pneumatically to distribution elements (also not shown) arranged at their end, which e.g. formed by coulters or impact plates, onto which the material to be distributed impinges, from where it can be laid on the ground in a fan-shaped manner. The distribution elements can be arranged on both sides, transverse to the direction of travel (in Fig. 1to the right and left) extending arms (not shown), wherein the distribution elements are arranged at different lateral distances from the storage container 1 and each distribution element is assigned a conveyor or distribution line of a bundle of conveyor or distribution lines.

[0033] In the Fig. 2 to 7 is an embodiment of a dosing unit 5 of the distribution machine according to Fig. 1 The dosing unit 5 comprises a dosing housing 20, which is designed, for example, essentially box-shaped or cuboid-shaped and has an inlet 21 arranged on its upper side (cf. the Fig. 2 and 3 ) and an outlet 22 arranged on its underside (see the Fig. 4). In the central area of ​​the metering housing 20, a metering roller 23 is rotatably mounted, which is suitable for distributing various types of distribution material, such as seed and / or fertilizer, and can be mounted in a conventional manner in a rotationally fixed manner on a central shaft (not shown), which in turn is connected to a controllable rotary drive (likewise not shown in the drawing) arranged outside the metering housing 20 in order to be able to set it in rotation at the desired speed.

[0034] As in particular the Fig. 15A and 15B in connection with the Figs. 6 and 7As can be seen, in the present embodiment, the metering roller 23 comprises, for this purpose, several - here three - metering wheel segments 23a, 23b, 23c, which are formed, for example, by cam or cellular wheel segments and have a different metering volume. In the present case, the metering wheel segment 23a is formed by a fine metering wheel segment, while the metering wheel segments 23b and 23c are formed by normal metering wheel segments, but nevertheless have a different metering volume - e.g. due to their different widths - so that very different mass flows of distributed material can be accommodated with one of the two metering wheel segments 23b, 23c or with both metering wheel segments 23b, 23c together. The metering wheel segments 23a, 23b, 23c are each separated from each other at their two axial ends by an annular wall 24 in order to prevent that the inlet 21 (cf. Fig. 2 and 3) the metering housing 20 can be fed from one metering wheel segment 23a, 23b, 23c into an adjacent metering wheel segment 23a, 23b, 23c. The metering roller 23 can be manufactured in one piece and can be provided with a central profile bore 25 (see the Fig. 15A ) are seated in a rotationally fixed manner on the central shaft (not shown) passing through them, or the metering roller 23 has separate metering wheel segments 23a, 23b, 23c and / or separate annular walls 24 which are individually mounted on the shaft (not shown), wherein at least the metering wheel segments 23a, 23b, 23c are in rotationally fixed engagement with the shaft by means of corresponding profile bores 25.

[0035] In order to be able to activate or deactivate individual metering wheel segments 23a, 23b, 23c of the metering roller 23 of the metering unit 5 independently of one another, each metering wheel segment 23a, 23b, 23c is assigned an independently operable shut-off valve 26, 27, 28, which each have an approximately circular arc-shaped inner circumference, in particular adapted to the outer circumference of a respective metering wheel segment 23a, 23b, 23c of the metering roller 23, and each in the circumferential direction (cf. the arrow P of the Fig. 5 ) of a respective metering wheel segment 23a, 23b, 23c of the metering roller 23 between a shut-off position (cf. the Fig. 3 right gate valve 26), in which they are arranged between the inlet 21 and the respective metering wheel segment 23a, 23b, 23c and put this metering wheel segment out of operation, and an open position (cf. the Fig. 3left gate valve 27, 28), in which the inlet 21 is connected to the respective metering wheel segment, can be actuated. The gate valves 26, 27, 28, which are located inside the metering housing 20 of the metering unit 5, can best be seen from the exploded views of the Figs. 6 and 7 are each individually subject to the Fig. 11 to 13 .

[0036] As can be seen there, each gate valve 26, 27, 28 in the embodiment shown comprises a shut-off part 26a, 27a, 28a with a circular arc-shaped inner circumference, which has a width adapted to the axial width of a respective metering wheel segment 23a, 23b, 23c of the metering roller 23 and extends around a sufficient circumferential section to completely cover the circumferential section of a respective metering wheel segment 23a, 23b, 23c of the metering roller 23 exposed to the inlet 21 of the metering housing 20 when the gate valve 26, 27, 28 is in its shut-off or closed position. In addition, each gate valve 26, 27, 28 comprises a bearing part 26b, 27b, 28b fastened to a circumferential side of a respective shut-off part 26a, 27a, 28a, which also has a circular arc-shaped inner circumference and serves to support a respective gate valve 26, 27, 28 in the interior of the metering housing 20.As explained in more detail below, the bearing part 26b, 27b, 28b of a respective gate valve 26, 27, 28 further comprises a fastening means - here in the form of a bore 26c, 27c, 28c - which serves to engage an actuating means in order to be able to displace a respective gate valve 26, 27, 28 in the circumferential direction of a respective metering wheel segment 23a, 23b, 23c. In the present exemplary embodiment, the shut-off parts 26a, 27a, 28a of the gate valves 26, 27, 28 further each have a shut-off surface inclined in the axial direction of the metering roller 23 and facing the inlet 21 of the metering housing 20, wherein the outer circumference of this shut-off surface of a respective gate valve 26, 27, 28 decreases inwards from a respective outer side of the metering housing 20 so that any residues of the material to be distributed do not remain on one or more gate valves 26, 27, 28 moved into the shut-off position, but can flow away. As best shown in the . Fig. 6as well as in the Figs. 11C, 12C and 13C As can be seen, the shut-off part 26a, 27a, 28a of a respective gate valve 26, 27, 28 has, for example, an approximately triangular cross-section for this purpose.

[0037] How best to use the Figs. 6 and 7 as well as from the detailed views of the Fig. 8 to 10 and 14 As can be seen, the dosing housing 20 of the dosing unit 5 in the embodiment shown is designed in several parts and comprises several housing parts that can be releasably fastened to one another, for example by means of screws, namely: a first end wall 20a of the metering housing 20, which has a central bore 29 for supporting the shaft (not shown) carrying the metering roller 23 and a plurality of fastening bores 30 in its peripheral area, which serve to receive the screws (also not shown) (cf. in particular the Fig. 8A to 8C); a central metering housing section 20b which is detachably fastened to the first end wall 20a and which in the present case extends essentially in an L-shape, forms the front wall and the lower wall of the metering housing 20 provided with the outlet 22 and has fastening holes 31 aligned with the fastening holes 30 of the first end wall 20a (cf. in particular the Fig. 9A to 9C ); a second end wall 20c which is detachably fastened to the side of the metering housing section 20b opposite the first end wall 20a and which - in this respect essentially corresponding to the first end wall 20a - has a central bore 32 for supporting the shaft (not shown) carrying the metering roller 23 and a plurality of fastening bores 33 in its peripheral area, which serve to receive the screws (also not shown) and are aligned with the fastening bores 30, 31 of the first end wall 20a and the metering housing section 20b, respectively (cf. in particular the Fig. 10A to 10C ); and a wall part 20d, which forms the rear wall opposite the front wall of the metering housing section 20b and which, on its upper side, together with the upper side of the front wall of the housing section 20b and the upper sides of the two end walls 20a, 20c, delimits the inlet 21 of the metering housing 20 (cf. in particular the Fig. 14A to 14C ). The wall part 20d is releasably secured to the housing section 20b, for example by means of screws (not shown), and comprises on its upper side, for example, a plane 37 which runs obliquely inwards and downwards and which delimits the inlet 21 of the metering housing 20 and whose contour is adapted to the gate valves 26, 27, 28 immediately adjacent to their free end, wherein the plane 37 serves as a stop for the free ends of the gate parts 26a, 27a, 28a when the gate valves 26, 27, 28 are in their shut-off or closed position.

[0038] As already mentioned, the gate valves 26, 27, 28 are mounted inside the metering housing 20, which in the present embodiment is done as follows. The end-face gate valve 26 associated with the metering wheel segment 23a - designed here as a fine metering wheel segment - is supported by means of its bearing part 26b, which has not only an approximately circular arc-shaped inner circumference, but also an approximately circular arc-shaped outer circumference and thus essentially has the shape of a partial circular ring, in a guide groove 34 complementary thereto (cf. in particular the Fig. 8A and 8Bor 11A to 11C) is mounted inside the end wall 20a of the metering housing 20 adjacent to the gate valve 26. Both the bearing part 26b of the gate valve 26 and the guide groove 34 of the end wall 20a of the metering housing 20 extend concentrically to the metering roller 23 in order to be able to displace the gate valve 26 in the circumferential direction of the metering roller 23 between its open and its shut-off position. In a largely corresponding manner, the end-side gate valve 28 assigned to the metering wheel segment 23c - designed here as a normal metering wheel segment - is mounted by means of its bearing part 28b, which likewise has not only an approximately circular arc-shaped inner circumference, but also an approximately circular arc-shaped outer circumference and thus essentially has the shape of a partial circular ring, in a complementary guide groove 35 (cf. in particular the Fig. 10A and 10Bor 13A to 13C) is mounted inside the end wall 20c of the metering housing 20 adjacent to the gate valve 28. Both the bearing part 28b of the gate valve 28 and the guide groove 35 of the end wall 20c of the metering housing 20 extend concentrically to the metering roller 23 in order to be able to displace the gate valve 28 in the circumferential direction of the metering roller 23 between its open and shut-off positions.

[0039] The gate valve 27 arranged between the gate valves 26, 28, which is assigned to the middle metering wheel segment 23b - here also designed as a normal metering wheel segment - is also mounted inside the metering housing 20, namely on a guide 36 of the metering housing section 20b, which has a guide surface complementary to the essentially circular arc-shaped inner circumference of the gate valve 27. In the present case, the guide surface of the guide 36 comprises two parallel rail elements extending along a circular arc, the distance between which corresponds to the axial width of the middle metering wheel segment 23b of the metering roller. In the assembled state, the two rail elements of the guide 36 are located directly radially outside the annular walls 24 axially delimiting the middle metering wheel segment 23b of the metering roller 23 (see also the Fig. 15A and 15B) and are aligned with them in order to guide the gate valve 27, but nevertheless leave the entire cross-section of the metering volume of the metering wheel segment 23b of the metering roller free. In addition, the gate valve 27 assigned to the middle metering wheel segment 23b of the metering roller 23 can be mounted on an axially adjacent gate valve - here: the gate valve 28 - which in the present case is achieved by complementary guide surfaces 38, 39 on the one hand of the gate valve 27, and on the other hand of the adjacent gate valve 28 on their mutually facing sides. The guide surfaces 38 and 39 are best seen in the Fig. 12C or Fig. 13C recognizable and essentially form a complementary step profile.

[0040] While the gate valves 26, 27, 28 can in principle also be manually operated independently of one another, for example by means of a handle which passes through the metering housing (not shown in the drawing), the gate valves 26, 27, 28 in the present embodiment are motor-operated independently of one another in a remote-controlled manner, for example by means of drive motors which are also not shown in the drawing. e.g.in the form of electric motors, which in the present embodiment are arranged outside the metering housing 20 of the metering unit 5, but can also be accommodated inside it (not shown). For this purpose, a respective drive of a respective gate valve 26, 27, 28 comprises a threaded spindle 40a, 40b, 40c mounted axially fixed but rotatable on an outer side of the metering housing 20 - here: on the one hand on one of the end walls 20a, 20c of the metering housing 20, on the other hand on the metering housing section 20b (see in particular the Fig. 2, 4 and 6), each of which can be rotated by a drive motor (not shown). The threaded spindles 40a, 40b, 40c each extend geometrically as a passant with respect to the metering roller 23 or with respect to the circular arc-shaped displacement path of a respective gate valve 26, 27, 28. Along each threaded spindle 40a, 40b, 40c, a spindle nut 41a, 41b, 41c is guided which engages therewith and is connected to a respective gate valve 26, 27, 28 in order to actuate the gate valve 26, 27, 28 by rotating the threaded spindle 40a, 40b, 40c and the resulting displacement of a respective spindle nut 41a, 41b, 41c in the axial direction of a respective threaded spindle 40a, 40b, 40c.In order to connect a respective spindle nut 41a, 41b, 41c to a respective gate valve 26, 27, 28 for the purpose of actuating the latter, an elongated hole 42a, 42b, 42c extends parallel to a respective threaded spindle 40a, 40b, 40c in the metering housing 20. Each elongated hole 42a, 42b, 42c is penetrated by a respective spindle nut 41a, 41b, 41c, wherein the spindle nut 41a, 41b, 41c is provided at its section engaging in a respective elongated hole 42a, 42b, 42c with a slot 43a, 43b, 43c extending approximately in the radial direction of a respective threaded spindle 40a, 40b, 40c (cf. the . Fig. 5), in which a respective gate valve 26, 27, 28 is articulated to the spindle nut 41a, 41b, 41c, for example by means of a pin (not shown) passing through a respective bore 26c, 27c, 28c of a respective gate valve 26, 27, 28, which pin is displaceable in the slot 43a, 43b, 43c of a respective spindle nut 41a, 41b, 41c in the direction of extension of this slot 43a, 43b, 43c. In this way, the distance changes due to the translational displacement of the spindle nut 41a, 41b, 41c along the threaded spindle 40a, 40b, 40c can be compensated for with respect to the rotational displacement of the gate valve 26, 27, 28 in the circumferential direction of the metering roller 23.

Claims

1. Metering unit (5) for powdered and / or particulate distribution material, in particular seed and / or fertilizer, the metering unit comprising a metering roller (23) having at least two metering wheel segments (23a, 23b, 23c), which roller is mounted in a metering housing (20) having an inlet (21) and an outlet (22), wherein an independently actuatable shut-off valve (26, 27, 28) is assigned to a relevant metering wheel segment (23a, 23b, 23c) in order to put one or more metering wheel segment(s) (23a, 23b, 23c) out of operation as required, wherein the shut-off valves (26, 27, 28) are mounted in the interior of the metering housing (20) and have a shut-off surface inclined in the axial direction, wherein the shut-off valves (26, 27, 28) have a substantially circular-arc-shaped inner circumference and can be actuated, in the circumferential direction of a relevant metering wheel segment (23a, 23b, 23c) of the metering roller (23), between a shut-off position, in which they are arranged between the inlet (21) and / or the outlet (22) and the relevant metering wheel segment (23a, 23b, 23c) and put the relevant metering wheel segment (23a, 23b, 23c) out of operation, and at least one open position, in which the inlet (21) and the outlet (22) are connected to the relevant metering wheel segment (23a, 23b, 23c).

2. Metering unit according to claim 1, characterized in that the outer circumference of the shut-off surface of a relevant shut-off valve (26, 27, 28) decreases inward from a relevant outer side of the metering housing (20).

3. Metering unit according to either claim 1 or claim 2, characterized in that the shut-off valves (26, 27, 27) can be actuated between the shut-off position, in which they are arranged between the inlet (21) and the relevant metering wheel segment (23a, 23b, 23c) and put the relevant metering wheel segment (23a, 23b, 23c) out of operation, and the at least one open position, in which the inlet (21) is connected to the relevant metering wheel segment (23a, 23b, 23c).

4. Metering unit according to any of claims 1 to 3, characterized in that a relevant shut-off valve (26, 27, 28) can be independently actuated by means of a corresponding handle, the handle in particular passing through the metering housing (20).

5. Metering unit according to any of claims 1 to 4, characterized in that an independently controllable and / or adjustable, in particular electromotive or actuating, drive is assigned to a relevant shut-off valve (26, 27, 28).

6. Metering unit according to claim 5, characterized in that the drive of a relevant shut-off valve (26, 27, 28) has a corresponding threaded spindle (40a, 40b, 40c) which can be rotated by a drive motor and along which a spindle nut (41a, 41b, 41c) which is in engagement with the threaded spindle (40a, 40b, 40c) is guided, which spindle nut is connected to a relevant shut-off valve (26, 27, 28) in order to actuate the shut-off valve (26, 27, 28) by rotating the threaded spindle (40a, 40b, 40c).

7. Metering unit according to claim 6, characterized in that the spindle nut (41a, 41b, 41c) has a slot (43a, 43b, 43c) extending substantially in the radial direction of the threaded spindle (40a, 40b, 40c), in which slot the shut-off valve (26, 27, 28) is articulated to the spindle nut (41a, 41b, 41c) in order to compensate for changes in distance caused by the translational movement of the spindle nut (41a, 41b, 41c) along the threaded spindle (40a, 40b, 40c) with respect to the movement of the shut-off valve (26, 27, 28) in the circumferential direction of the metering roller (23).

8. Metering unit according to any of claims 5 to 7, characterized in that the drive of a relevant shut-off valve (26, 27, 28) - is arranged outside the metering housing, the threaded spindles (40a, 40b, 40c) being mounted in particular on an outer side of the metering housing (20); or - is arranged within the metering housing, the threaded spindles (40a, 40b, 40c) being mounted in particular on the inside of the metering housing (20).

9. Metering unit according to any of claims 1 to 8, characterized in that at least one end-face shut-off valve (26, 28), in particular both end-face shut-off valves (26, 28), is or are mounted in a guide groove (34, 35) in the interior of an end wall (20a, 20c) of the metering housing (20).

10. Metering unit according to any of claims 1 to 9, characterized in that the metering roller (23) has at least three metering wheel segments (23a, 23b, 23c), a corresponding shut-off valve (26, 27, 28) being assigned to a relevant metering wheel segment (23a, 23b, 23c).

11. Metering unit according to claim 10, characterized in that at least one shut-off valve (27) assigned to at least one central metering wheel segment (23b) is mounted on a guide (36) arranged in the interior of the metering housing (20), which guide has a guide surface complementary to the substantially circular-arc-shaped inner circumference of the shut-off valve (27).

12. Metering unit according to claim 11, characterized in that the guide (36), which is arranged in the interior of the metering housing (20), of the shut-off slide valve (27) assigned to the at least one central metering wheel segment (23b) is arranged on a metering housing portion (20b) which is detachably connected to at least one end wall (20a, 20c), in particular to both end walls (20a, 20c), of the metering housing (20).

13. Metering unit according to any of claims 10 to 12, characterized in that at least one shut-off valve (27) assigned to at least one central metering wheel segment (23b) is mounted on an axially adjacent shut-off valve (28), the axially adjacent shut-off valves (27, 28) in particular having mutually complementary guide surfaces (38, 39).

14. Metering unit according to any of claims 1 to 13, characterized in that the metering wheel segments (23a, 23b, 23c) of the metering roller (23) - are separated from one another at the mutually facing axial ends thereof by means of an annular wall (24); and / or - are formed by cam and / or cell wheels, which in particular have a different metering volume.

15. Distribution machine, in particular seed spreader or fertilizer spreader, characterized by at least one metering unit (5) according to any of claims 1 to 14.